Missile launcher
, a tripod-mounted infantry ATGM system.]] A missile launcher is a weapon which fires a self-powered guided projectile. It is distinct from a rocket launcher, which fires a self-powered unguided projectile, though in less formal use the terms are often treated as interchangeable. Infantry guided missiles are typically either launched rested on top of the gunner's shoulder, or from a tripod or similar mounting. History The fundamentals of guided missile research date back to the first experiments in radio control in the last decade of the 19th century. The first weapons to be radio-controlled were naval torpedoes, with the first examples demonstrated in 1909. By the 1930s, radio control was a sufficiently mature technology that the Soviet military had already fielded remote controlled "teletanks" in combat, while the British Royal Navy employed full-sized remote-controlled Tiger Moth biplanes as gunnery targets. Research in applying this technology to the control of missiles and bombs began in the 1930s with the first prototype systems developed during the closing years of the Second World War. However, missile systems were restricted to vehicle use until the late 1950s due to the challenge of miniaturizing a guidance system to the point infantry could reasonably carry it. The advent of the transistor was a great step forward in this regard. The first infantry missile systems still used missiles too large for an enclosed gun-like launcher, instead being launched from a portable firing rail or their own carrying box. Typically for transport the missile would be split down into warhead and motor assembly to allow for a smaller carrying box, which allowed for easy upgrades to the warheads of these systems. The first such system to be issued in quantity was the French Nord Aviation SS.10 (Sol-Sol, "Surface to Surface"), a box-launched system. This was based on WW2 German work on a rail-launched wire-guided manual command line of sight (MCLOS) anti-tank missile for aircraft called the Ruhrstahl X-7. This system entered service with the French military in 1955, with the improved SS.11 entering service a year later: however, an infantry version of the latter as not produced until 1962. It was not widely successful, as potential clients compared the system's 1,750-yard maximum range to the 2,200-yard range of period ant-tank guns. Another French box-launched system, ENTAC (ENgin Téléguidé Anti-Char, "Remote controlled engine, anti-tank"), entered service in 1957. The US military adopted both the SS.10 (on a limited basis) and ENTAC, under the designations MGM-21A and MGM-32A. The Soviet Union acquired examples of these systems, along with the Swiss Cobra ATGM that had entered service in 1957. The Kolomna Machine Design Bureau, who had already built the 3M6 Shmel (Шмель, "Bumblebee," NATO reporting name AT-1 Snapper) vehicle-mounted ATGM, were directed to produce a similar man-portable MCLOS system. In 1963 they produced the first variant of the 9M14 Malyutka (Малютка, "Little One" NATO reporting name AT-3 Sagger) anti-tank missile, one of the most widely-produced ATGMs of all time. Britain started work on its own portable MCLOS missiles system in 1956, the Vickers Vigilant (VIsually Guided Infantry Light ANti-Tank), as a replacement for the bulky and ineffective Malkara vehicle-mounted missile system. The Vigilant entered service in the early 1960s, though by 1966 it was already being phased out in favor of the Swingfire missile. The US Marine Corps also acquired a production license for the Vigilant. The US military began studies of a second-generation guidance system for ATGMs at Redstone Arsenal starting in January 1957, quickly settling on the idea of a tube-launched, optically tracked, wire guided missile, a concept described by the acronym TOW and a type of semi-active command line of sight (SACLOS) guidance. Three roles were identified for new ATGM systems, heavy antitank weapon (HAW), a crew-served support weapon to replace SS.10, ENTAC and the M40 recoilless rifle, medium antitank weapon (MAW), a more portable infantry system to replace the M67 recoilless rifle, and combat vehicle weapon system (CVWS), a missile that could be fired from either a tube launcher or a closed-breech gun launcher. The TOW label would eventually become associated only with the HAW, which became the BGM-71 TOW and entered service in 1970, while the MAW would become the M47 Dragon, the world's first man-portable shoulder-launched anti-tank missile, entering service in 1974. In the mid-1950s the US-based Convair aircraft company had begun studies of a man-portable surface-to-air missile to combat fast jets, and in 1957 the US military laid out the first official requirements for the system: Convair was awarded a contract to start development on what would become the FIM-43 Redeye MANPADS in 1958, using a seeker adapted from the AIM-9B Sidewinder air-to-air missile. The Soviet Union learned of this program as it was nearing completion and supplied information on it to Turopov OKB, who started work on their own first-generation MANPADS, the 9K32 Strela-2 (Cтрела, "Arrow," NATO reporting name SA-7 Grail), in 1964. Production was eventually switched over to the Kolomna Machine Design Bureau. Redeye entered limited production in 1962 though the final mass-production FIM-43C was not produced until 1968, while the SA-7 was accepted for service in 1968 with full production starting in 1970. Due to the limitations of period IR sensors, both systems were of a type known as "hot metal trackers," only able to detect the incandescent metal inside a target jet aircraft's engine nozzle. code for the full system is 9K111.]] The Soviet Union began work on a counterpart to the American SACLOS anti-tank missile programs in 1962, choosing to develop two different missile systems which would use a common launcher: these were the smaller 9M111 Fagot (Фагот, "Bassoon," NATO reporting name AT-4 Spigot) and larger 9M113 Konkurs (Конкурс, "Contest," NATO reporting name AT-5 Spandrel). The AT-4 was first fielded in 1970, the same year the American BGM-71 TOW entered service, while the AT-5 took another four years: as a result, the first generation 9P135 launcher cannot fire the AT-5. The Soviet counterpart to the Dragon, 9M115 Metis (метис, roughly "mixed-race," NATO reporting name AT-7 Saxhorn) was introduced in 1978. France also started development of a SACLOS wire-guided missile system in 1962, the MILAN (Missile d'infanterie léger antichar, "Light anti-tank infantry missile," also a pun on the French word for "kite" in reference to the missile being wire-guided). This system entered service in 1972, and was widely exported, seeing service with many NATO militaries. The first generation of MANPADS had proven to be inefficient and easily spoofed by countermeasures, and in the late 60s and early 70s a number of nations commenced programs to either make better IR seeking missiles or create weapons with seeker systems that were harder to defeat. The Soviet Union began a program in 1964 to produce a both an incremental and a large-scale upgrade to the SA-7, the latter resulting in the 9K34 Strela-3 (NATO reporting name SA-14 Gremlin) in 1974. The US started work on a similar upgrade to Redeye in 1967, producing the FIM-92 Stinger in 1978. Other nations focused instead on line-of-sight guided weapons, such as the British MCLOS Shorts Blowpipe and its SACLOS successors, and the Swedish line of sight beam riding (LOSBR) RBS 70. China had largely made do with copies of Soviet systems prior to initiating their first domestic ATGM program in 1970, aiming to replace the Hongjian-73 (红箭, "Red Arrow," a copy of the Soviet AT-3 Sagger) with a SACLOS system. The result, the Hongjian-8, was derived in roughly equal parts from MILAN (tracker), TOW (tripod) and Swingfire (missile). In the mid 70s Japan began work on a pair of ATGM systems to replace the obsolete vehicle-mounted MCLOS Type 64 MAT (missile, anti-tank). Their designers were given the unusual stipulation that it should be possible to detach the sighting unit from the launcher and fire the system remotely: this is a very common feature of MCLOS missiles, but very rare for a portable SACLOS system. The smaller Type 79 Jyu-MAT, a system roughly equivalent to MILAN, used a standard IR SACLOS system with the sight unit able to be placed up to 55 yards (50 meters) from the launcher. The larger Type 87 Chu-MAT was roughly equivalent to TOW, and had an even more unusual feature: it was a semi-active laser homing (SALH) missile system, with the sight unit a portable laser designator. This allowed the system to function with the sight unit placed up to 220 yards (200 meters) from the launcher. The missile launch tubes featured an integral stand with frontal bipod legs, allowing them to simply be deployed on the ground while the system's tripod was used for the designator, or even shoulder-fired by infantry coordinating with the team handling the laser. In the mid-to-late 70s a new generation of MANPADS began development, with the first examples appearing in the early 80s: these third-generation missiles used multi-band seekers to improve their performance against flares, and new seeker-scanning techniques to provide improved performance in cluttered environments. The dual-band IR/UV FIM-92B Stinger POST (passive optical seeker technique, a term for rosette scanning) entered service in 1983, as did the Soviet 9K38 Igla (Игла́, "needle," NATO reporting name SA-18 Grouse). A simplified version of the latter, the 9K310 Igla-1 (NATO reporting name SA-16 Gimlet), had already been in service for two years, but used the IR seeker from the SA-14 Gremlin. The French MBDA Mistral missile system followed in 1988, a "heavy" MANPADS like the RBS-70 which was fired from a tripod with a gunner's seat. anti-tank missile. The EFP warhead is the diagonal structure in the missile's midsection.]] In 1979, anticipating possible future developments in tank armor, the Swedish company Bofors AB began work on the first man-portable system to use an overfly top-attack (OTA) flightpath, resulting in the RBS 56 BILL (Bofors, Infantry, Light & Lethal) missile in 1985. Rather than using an impact warhead, this system would fly over the target and launch a solid explosively formed penetrator (EFP) into the weak top armor of the tank, piercing the turret roof or engine deck. Actual guidance for the BILL was SACLOS, with the warhead triggered by a proximity fuze. The later RBS 56B BILL 2 upgraded the system to have two EFP warheads, the front a 40 mm precursor and the rear a 110 mm primary penetrator, in order to defeat upward-facing ERA, and added additional impact and soft (non-metallic) target engagement modes, the latter simply disabling the warhead's magnetic detonation sensor. The BILL inspired a number of later OTA systems, including the TOW-2B, FGM-172A SRAW and MBT LAW. A flurry of ATGM development took place following the introduction of the Israeli Blazer explosive reactive armor in 1982 and the first iteration of the Soviet Kontakt series in 1984, with many existing infantry missile systems being reworked to carry tandem-charge warheads over the following years. It was also clear that this would be a necessary feature for all future systems using HEAT warheads. In 1983 America commenced the Advanced Antitank Weapon System - Medium (AAWS-M, pronounced "awesome") program with the goal of designing a next-generation portable anti-tank weapon to replace the ineffective and obsolete M47 Dragon. This project was heavily monitored by other states: while the main design became the FGM-148 Javelin, the LOSBR Ford Aerospace design was highly influential in the development of the Russian 9M133 Kornet (Корнет; "Cornet," NATO reporting name AT-14 Spriggan) the imaging infrared/fiber-optic Hughes AAWS-M submission influenced the development of the Israeli Rafael Spike, particularly the launch unit, and the 1986 Texas Instruments/Martin Marietta proof-of-concept demonstrator, lighter and simpler than the final Javelin, inspired the Japanese Type 01 LMAT. Following the end of the Cold War American MANPADS development and deployment stagnated, with the fourth-generation Stinger RMP Block II being cancelled for budgetary reasons in 2002 and no current plans to develop such a system. Several other nations have developed and deployed fourth-generation MANPADS, however, the first being Japan's Type 91 in 1994. Others include the Chinese QW-4 and the 2011 Russian 9K333 Verba (Верба, "Willow," NATO reporting name SA-25, the "G" brevity name is currently classified) which replaced the Igla series in service. While not a part of the regular "generation" structure, Britain and Sweden also produced advanced LOSBR MANPADS, respectively the Starstreak (first deployed as a shoulder-launched system in 2000) and the BOLIDE missile for the RBS 70 in 2003, with the RBS 70 also receiving the improved NG ("new generation") launcher in 2011. The period of asymmetric warfare following the beginning of the War on Terror in 2001, with opposing forces rarely having any meaningful access to modern armored vehicles, resulted in the development of alternative munitions for ATGM systems. These focused on effectiveness against reinforced structures or anti-infantry effect through the use of dual-purpose warheads with fragmentation elements, or thermobaric warheads. Types While there are many types of guided missile system, infantry systems typically fall into the following two categories: ATGM An Anti-Tank Guided Missile system is designed to engage ground-based armored vehicles. Infantry ATGM systems usually subdivide into "portable" and "heavy," the latter being somewhat analogous to heavy machine guns in their employment and limitations. In many schemes of military classification, the "weight" categories are for antitank weapons in general rather than just missiles: shoulder-fired ATGMs are "medium," while "light" usually refers to small rocket launchers or recoilless guns like the RPG-22 or AT4. The term MANPATS (MAN Portable Anti Tank System) is similarly not restricted to missiles. Due to the large size requirement to carry an effective hollow-charge or explosively formed penetrator warhead, they are not fast or manoeuvrable enough to attack fixed-wing aircraft, though they are often suitable for attacking helicopters. ATGMs are roughly divided into "generations:" * Generation 1: MCLOS, wire-guided, usually box-launched. * Generation 2: SACLOS, usually wire-guided, tube-launched. * Generation 3: Wireless fire-and-forget. Sometimes also includes SALH. "Fourth generation" is a term generally associated with the Rafael Spike, but is not particularly well-defined: some attempts at creating a meaningful definition make SACLOS generation 2 and tube-launched SACLOS generation 3 or place tandem-charge warheads in the third generation and fire-and-forget in the fourth. Other sources simply call Spike a third-generation system. The French MBDA Missile Moyenne Portée is marketed as a "fifth-generation" system, and some press associated with the Spike-ER II uses the term too. MANPADS MANPADS.]] A MAN Portable Air Defense System is an infantry missile launcher designed to engage aircraft. The term SHORAD (SHOrt Range Air Defense) is sometimes also used in connection with them, though this is a more general role classification that can also include anti-aircraft guns. They are typically not suited to engaging vehicles due to their use of fragmentation warheads, though a few examples have a limited dual-purpose functionality due to using kinetic penetrators or hollow charge warheads. Most examples are shoulder-launched, though there are examples of "heavy" MANPADS which use a tripod stand with a gunner's seat and are only portable when dismantled, with several soldiers carrying the system and assembling it at the desired launch site. Homing fire-and-forget MANPADS are also regarded as having generations: * Generation 1: Uncooled spin-scan lead sulfide seeker, limited IR spectrum "hot metal seeking," tail-chase only, little or no ability to distinguish flares. "Noisy" detector leads to trouble dealing with IR scattering and limits the system's usefulness in harsh weather or at night. Seeker design often leads to erratic missile behavior in the terminal stage of engagement. * Generation 1.5: Label applied to later versions of FIM-43 Redeye which have a gas-cooled seeker but still use spin-scan detectors. * Generation 2: Supercooled lead sulfide, iridium antimonide or mercury cadmium telluride detector. Improved image discrimination from this plus the use of a conical scanning seeker allows a limited ability to lock onto airframes rather than just engines, and much better sensor noise reduction improves all-weather capability. * Generation 3: Pseudo-imaging rosette scanning with dual-channel IR or combined IR/UV, improving resistance to ECM. All-weather and all-aspect capable, though frontal engagement is usually inferior to side or rear. * Generation 4: Full-imaging IR focal plane array/FLIR or combined imaging IR/UV seeker. Fully all-aspect capable. Generation labels are not applied to MANPADS using command line of sight guidance. Launch modes and backblast .]] As with rocket systems, missiles are described as having one of two launch modes, either hot/hard launch, where the main booster fires immediately, or a cold/soft launch where a smaller launch motor fires to eject the missile from its casing, with the main booster firing after a short delay allows the missile to clear its launch site. The "cold" term is usually applied to silo and VLS launched missiles rather than infantry systems. Modern infantry missile systems use soft launch exclusively. "Soft" launch is only in relative terms, and such missiles still have significant areas behind them where potentially lethal blast and overpressure are generated by the firing of the launch motor. All such missiles will also have a "caution zone" extending further than the danger area where the primary backblast may still cause injury by hurling debris. Firing from indoor enclosures usually requires some efforts to be made to sweep up debris, open doors and in some cases even smash holes in walls to prevent harm to the crew or structural damage to the building from overpressure, though some modern launchers are designed to be simpler to fire from confined spaces. The effects are not confined to physical injury: the use of hearing protection is vital when employing a missile system to avoid permanent deafness. Missiles, much like rockets and HE grenade rounds, typically use some form of delay arming system to prevent the warhead detonating dangerously close to the operator. On soft-launch weapons there is usually an inertial element to the arming system with the G-force of the main booster igniting acting on the arming mechanism to render the weapon live, meaning in the case of a flight motor failure the warhead cannot detonate. Missiles often have a longer delay before they are capable of actually tracking a target, either because the system's tracker needs to "capture" the missile within its field of view before it can be guided, or because the missile is still readying its internal electronics or following an initial autopilot phase. First-generation MCLOS anti-tank missiles were particularly known for the very substantial "deadzone" around the launcher, to the point that one member of a three-man Soviet AT-3 Sagger fireteam would carry an RPG-7 as part of his combat load to deal with targets their launcher could not hit. Guidance All missile guidance techniques fit into two super-categories, called GOLIS (go onto location in space) and GOT (go onto target). GOLIS guidance, such as inertial and satellite, manoeuvres the missile to a fixed location. It is not typically used on infantry systems, normally being restricted to weapons such as ICBMs and cruise missiles, though some overfly top attack (OTA) missiles like FGM-172A SRAW and MBT LAW use a GOLIS method, namely pre-programming an autopilot using the measured motion of the target as detected by the launcher. The missile in this system does not use sensor data to steer itself after launch: rather, the target detection system is only used to detonate the warhead, having no role in guidance. This method is called predicted line of sight (PLOS). GOT, on the other hand, tracks a specific target, and so GOT guidance methods are far more commonly used for attacking mobile targets. There are many subtypes of GOT guidance. Command line-of-sight guidance Command Line-of-sight (CLOS) guidance is where the sight (called a "tracker" in most such systems) designates a target within its own field of view, remotely directing the missile to the system's sightline. The missile is "commanded" in that it is relayed signals from the tracker, either through trailing command wires or fiber-optic cables (wire-guided missiles) or through a transmission method such as radio (referred to as RF guidance, "radio frequency"). Command line-of-sight is the most common guidance method for anti-tank missiles, and also used on some anti-aircraft missiles. * MCLOS - Manual command line of sight. No element of the system is automated: the operator must directly steer the missile using a device such as a joystick, while keeping track of both it and the target. This was the first system of missile guidance developed, used with early guided weapons such as the German Wasserfall SAM and Fritz-X glide bomb, and the American AZON guided bomb. **TV guidance - Television guidance. Subtype of MCLOS where the operator steers the missile using a camera in its nose rather than by tracking it from their own position. * SMCLOS - Semi-manual command line of sight. Missile is steered directly, but either missile tracking or target tracking is automated. * SACLOS - Semi active command line of sight or semi automatic command line of sight. One element of the system is an active beacon or designator and the other is a passive detector that tracks it. ** IR SACLOS - A thermal detector in the launcher tracks a beacon on the missile's tail, generating course corrections to steer it to the tracker's point of aim. ** LOSBR - Line of sight beam riding. The launcher aims a conical radar, radio or laser beam at the target created by rapid scanning, with the missile using a sensor in its tail to detect the scanning of the beam, using this information to steer itself into the middle of the cone. * ACLOS - Automatic command line of sight. Target tracking, missile tracking and guidance are all automated. Homing systems Homing guidance systems have the missile generate its own guidance commands, removing the need for a direct connection between launcher and missile. They subdivide into active homing, in which the missile emits energy of some kind and tracks its reflection from the target, semi-active homing in which the missile tracks energy from an active emitter on either its launch platform or a third-party source, and passive homing, where the missile detects energy emitted by the target only. Active homing requires the missile contain an active emitter, detector, a power supply for both and all the equipment needed to process their signals. The weight and cost restricts active homing to use on air-to-air and anti-ship missiles, and it has yet to be used in any portable system. In a semi-active homing system, the target is illuminated with a designator, either a radar beam (semi-active radar homing, SARH) or a laser (semi-active laser homing, SALH). A passive detector in the missile's nose detects the reflected energy and generates course corrections to intercept the source. The designator can either originate from the launching platform, or from a third-party designator: in some systems like the SALH Hellfire missile, this allows the weapon to be launched "blind" and acquire a target not within the launching platform's line of sight. This functionality is called lock-on after launch (LOAL). The most common method of passive homing is contrast detection, where a detector, either visual-range or more often UV or thermal, looks for areas within its field of view that are significantly brighter or darker than their surroundings, generating course corrections to steer towards an anomaly and intercept it. Modern MANPADS often compare the output of two widely separated IR bands or IR with other types of radiation such as UV or radar so as to defeat countermeasures. Modern tracking systems may assist the contrast detector using some type of tracking gate system, which allows the operator to manually narrow the initial search area: for example, FGM-148 Javelin has the operator draw a box around the desired search area by adjusting track gate markers at its four corners, while designating the target's center of mass with a crosshair. Countermeasures Both ATGMs and MANPADS are serious threats to the platforms they are designed to attack, and a number of different systems have been developed to counteract them, roughly divided into "soft kill" or "passive" and "hard kill" or "active" systems. Typically anti-ATGM hard-kill systems can also intercept RPGs and large-caliber gun rounds, while anti-MANPADS systems are also effective against other types of heat-seeking anti-aircraft missiles. Soft kill Soft kill systems aim to interfere with the guidance of the missile or the ability of its operators to engage the target. Against MCLOS there is no effective soft kill method aside from visually screening the target with smoke so that the missile's operators cannot see it to engage it. Defensive manoeuvres such as sharp turns and erratic stops and starts were often used to prevent a human operator correctly anticipating the target's motion, as MCLOS was notoriously difficult to direct against a moving target even under ideal conditions. SACLOS using infra-red is difficult to detect, but if the launch is spotted or the missile is detected on approach and the launch site known, it is possible to blind the launcher by directing an IR lamp at it, causing it to lose track of the missile's IR beacon: for this to work, the system has to emit IR in the same frequency band as the missile's IR lamp. This sort of system is more normally used against SALH missiles, however, since then it can be directed at the seeker head of the missile itself. SALH can also be defended against with smoke, as this will obscure the reflected light the missile's seeker is trying to detect. Laser blinders can also be used to damage the optics of missile systems, either on the missile itself or the tracker (or the gunner, though the latter is prohibited under international law by the 1995 Protocol on Blinding Laser Weapons), though filter systems can be used to defend against this. LOSBR weapons are notoriously difficult to counter due to their tracker facing directly away from the target and their use of low-energy lasers for guidance, with a typical LOSBR system having less than 1% of the energy at target of a SALH designator of equivalent effective range. High-sensitivity laser illumination detection systems using advanced scanning techniques have been produced, but at present these are primarily for use on aircraft, particularly helicopters, and are linked to warning systems to give a chance to perform evasive manoeuvres. In general, homing weapons are most prone to soft-kill countermeasures since the defender only has to trick a machine rather than a human operator: the first such system was air-launched flares, designed to distract an IR-seeking SAM or air-to-air missile by presenting it with a false target which was much hotter than the deploying aircraft's engines. In early MANPADS the only real counter to this was using a narrow-angle seeker in the hope it would never "see" the flare at all, but newer systems use dual or multi-band scanning to detect flares. Modern IR countermeasure (IRCM) devices use more sophisticated illuminators which are designed to temporarily give the missile a false target, in the hope that it will steer towards it for long enough that the targeted aircraft is no longer within the missile's seeking angle. SAM and AAM seeker design is a constant arms race between decoy design and increasingly sophisticated methods of distinguishing a decoy from a real target. Hard kill Hard kill systems destroy the missile in flight or try to prevent proper functioning of the warhead. The earliest thing that could be considered a hard-kill anti-missile countermeasure was the use of coordinated suppressing fire against ATGM teams using MCLOS or SACLOS weapons, aiming to either kill the crews or force them to abandon their launcher while the missile was still in flight. The first purpose-designed system was explosive reactive armor (ERA). In this system, "blocks" consisting of a layer of explosive between two armor plates are placed over the vehicle's main armor layer. When a warhead strikes them, the explosive layer detonates, firing the outer plate forwards. This is primarily designed to disrupt the formation of a hollow-charge warhead's high-speed kinetic jet, as this requires a proper standoff distance to be effective, but can also cause kinetic penetrators to split apart or yaw, reducing their effectiveness. Early ERA had numerous flaws, in particular that it could induce spallation in the vehicle it was supposed to protect. Spallation (also known as spalling) is a phenomenon where an external impact sends shockwaves through solid material, causing sections of its interior surface to break off. This was a problem with cast-metal tank armor (modern composite is a poor conductor of shockwaves) and could potentially injure crew or damage the vehicle. However, as ERA became effective, tandem-charge warheads designed to deal with it became common, with modern ERA systems often including multiple layers of blocks to address this threat. Non-explosive reactive armor (NERA or NxRA) has been developed as well: this armor, rather than using an explosive liner, uses a layer such as rubber which causes the exterior plating to bulge outwards and disrupt the jet. As well as being safer for infantry nearby due to not firing off large metal plates from the surface of the vehicle, this type of armor cannot be defeated by tandem charges. However, it is less effective than an ERA plate of similar mass. Armored vehicle "active protection systems" (APS) using kill methods analogous to shotguns, grenade launchers or antipersonnel mines have also been developed, usually using a radar detector to locate an approaching missile and then launching one or more projectiles at it to destroy or break up the warhead. These systems can be factored into a vehicle's general fire control systems: the Israeli Trophy APS, for example, can be set to automatically lay a tank's main gun in the direction a projectile approached from to prepare for a counter-shot. Typically an APS compliments armor rather than replacing it, as high-speed fragments of the missile will still impact the vehicle. Many modern tanks use a three-layered defense with APS, ERA and then finally the vehicle's layered composite armor. Recently research has focused on creating similar hard-kill APS for helicopters to protect them from MANPADS and RPGs, though as yet none are in service. References Category:Missile launchers Category:Firearms by type